Method of forming a 3-dimensional fiber and a web formed from such fibers

ABSTRACT

A method of forming 3-dimensional fibers is disclosed along with a web formed from such fibers. The method includes the steps of co-extruding a first component and a second component. The first component has a recovery percentage R 1  and the second component has a recovery percentage R 2 , wherein R 1  is higher than R 2 . The first and second components are directed through a spin pack to form a plurality of continuous molten fibers. The molten fibers are then routed through a quenching chamber to form a plurality of continuous cooled fibers. The cooled fibers are then routed through a draw unit to form a plurality of continuous, solid linear fibers. The solid fibers are then accumulated and stretched by at least about 50 percent. The plurality of stretched fibers are then cut and allowed to relax such that a plurality of 3-dimensional, coiled fibers is formed.

BACKGROUND OF THE INVENTION

[0001] There are numerous methods known to those skilled in the art forspinning fibers that can be later formed into a nonwoven web. Many suchnonwoven webs are useful in disposable absorbent articles for absorbingbody fluids and/or excrement, such as urine, fecal matter, menses,blood, perspiration, etc. Three dimensional fibers are also useful formachine direction and cross direction stretchable spunbond materialsthat can be made into bodyside covers, facings and liners. Manufacturersof such articles are always looking for new materials and ways toconstruct or use such new materials in their articles to make them morefunctional for the application they are designed to accomplish. Thecreation of a web of 3-dimensional, bicomponent fibers wherein thefibers are formed from at least one elastomeric material that can extendin at least one direction can be very beneficial. For example, an infantdiaper containing an absorbent layer formed from cellulose pulp fibersinterspersed into a web of 3-dimensional nonwoven fibers will allow theabsorbent layer to retain a larger quantity of body fluid if the3-dimensional fibers can expand. Such an absorbent layer can providebetter leakage protection for the wearer and may not have to be changedas often. In another example, a spunbond nonwoven facing or liner formedfrom a plurality of 3-dimensional fibers can provide improved stretchand controllable retraction. Such facings or liners can provide improvedfit and better comfort for the wearer of absorbent articles.

[0002] A web formed from such 3-dimensional fibers can provide one ormore of the following attributes: improved fit, improved loft, bettercomfort, greater void volume, softer feel, improved resiliency, betterstretch, controlled retraction and improved absorbency.

[0003] The exact method utilized in forming a nonwoven web can createunique properties and characteristics in the web which can not beduplicated in another manner. Now, a new method of forming a3-dimensional fiber has been invented which allows the fibers to belater formed into a web that can exhibit very desirable properties whichare useful when the web is incorporated into a disposable absorbentarticle.

SUMMARY OF THE INVENTION

[0004] Briefly, this invention relates to a method of forming3-dimensional fibers along with a web formed from such fibers. Themethod includes the steps of co-extruding a first component and a secondcomponent. The first component has a recovery percentage R₁ and thesecond component has a recovery percentage R₂, wherein R₁ is higher thanR₂ The first and second components are directed through a spin pack toform a plurality of continuous molten fibers. The plurality of moltenfibers is then routed through a quenching chamber to form a plurality ofcontinuous cooled fibers. The plurality of cooled fibers is then routedthrough a drawing unit to form a plurality of continuous, solid linearfibers. The plurality of the solid fibers is then accumulated on a spoolthat can be at a later time unwound and stretched by at least about 50percent. The plurality of stretched fibers are then cut and allowed torelax such that a plurality of 3-dimensional, coiled fibers is formed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 is a schematic showing the equipment needed to extrude,spin, quench and draw continuous solid fibers and accumulate them on aspool.

[0006]FIG. 2 is a cross-section of a bicomponent fiber.

[0007]FIG. 3 is a schematic showing unwinding a plurality of solidlinear fibers, stretching the fibers, cutting the fibers and thenallowing the fibers to relax to form a plurality of 3-dimensional,staple fibers.

[0008]FIG. 4 is a side view of a helical fiber formed when the stretchedfiber is cut into a staple fiber and the fiber is allowed to relax.

DETAILED DESCRIPTION OF THE INVENTION

[0009] Referring to FIG. 1, a schematic of the equipment needed toextrude, spin, quench and draw a plurality of continuous solid fibersand accumulate them on a plurality of spools is depicted. The methodincludes the steps of co-extruding a first component 10 and a secondcomponent 12. The first and second components, 10 and 12 respectively,can be in the form of solid resin pellets or small particles. The firstcomponent 10 is positioned in a hopper 14 from which it can be meteredand routed through a conduit 16 to a first extruder 18. Likewise, thesecond component 12 is positioned in a hopper 20 from which it can bemetered and routed through a conduit 22 to a second extruder 24.

[0010] The first component 10 is a material that can be spun orotherwise formed into a continuous fiber. When the first component 10 isformed into a fiber, the fiber must be capable of being stretched andhas a high recovery percentage R₁. The “recovery percentage R₁” isdefined as the percent the first component 10 can recover after it hasbeen stretched at least about 50% of its initial length and upon removalof the force applied to stretch it. Desirably, the first component 10 isan elastomeric material. Suitable elastomeric materials that can be usedfor the first component 10 include a melt extrudable thermoplasticelastomer such as a polyurethane elastomer, a copolyether ester, apolyether block polyamide copolymer, an ethylene vinyl acetate (EVA)elastomer, a styrenic block copolymer, an ether amide block copolymer,an olefinic elastomer, as well as other elastomers known to thoseskilled in the polymer art. Useful elastomeric resins include polyesterpolyurethane and polyether polyurethane. Examples of two commerciallyavailable elastomeric resins are sold under the trade designations PN3429-219 and PS 370-200 MORTHANE® polyurethanes. MORTHANE® is aregistered trademark of Huntsman Polyurethanes having an office inChicago, Ill. 60606. Another suitable elastomeric material is ESTANE®, aregistered trademark of Noveon, Inc. having an office in Cleveland, Ohio44141. Still another suitable elastomeric material is PEARLTHANE®, aregistered trademark of Merquinsa having an office in Boxford, Mass.01921.

[0011] Three additional elastomeric materials include a polyether blockpolyamide copolymer which is commercially available in various gradesunder the trade designation PEBAX®. PEBAX® is a registered trademark ofAtofina Chemicals, Inc. having an office in Birdsboro, Pa. 19508. Asecond elastomeric material is a copolyether-ester sold under the tradedesignation ARNITEL®. ARNITEL® is a registered trademark of DSM havingan office at Het Overloon 1, NL-6411 TE Heerlen, Netherlands. The thirdelastomeric material is a copolyether-ester sold under the tradedesignation HYTREL®. HYTREL® is a registered trademark of E. I. DuPontde Nemours having an office in Wilmington, Del. 19898.

[0012] The first component 10 can also be formed from a styrenic blockcopolymer such as KRATON®. KRATON® is a registered trademark of KratonPolymers having an office in Houston, Tex.

[0013] The first component 10 can further be formed from a biodegradableelastomeric material such as polyester aliphatic polyurethanes orpolyhydroxyalkanoates. The first component 10 can be formed from anolefinic elastomeric material, such as elastomers and plastomers. Onesuch plastomer is an ethylene-based resin or polymer sold under thetrade designation AFFINITY®. AFFINITY® is a registered trademark of DowChemical Company having an office in Freeport, Tex. AFFINITY® resin isan elastomeric copolymer of ethylene and octene produced using DowChemical Company's INSITE™ constrained geometry catalyst technology.Another plastomer is sold under the trade designation EXACT® whichincludes single site catalyzed derived copolymers and terpolymers.EXACT® is a registered trademark of Exxon Mobil Corporation having anoffice at 5959 Las Colinas Boulevard, Irving, Tex. 75039-2298. Othersuitable olefinic elastomers that can be used to form the firstcomponent 10 include polypropylene-derived elastomers.

[0014] The first component 10 can further be formed from anon-elastomeric thermoplastic material which has a sufficient recoverypercentage R₁ after it has been stretched at a specified temperature.Non-elastomeric materials useful in forming the first component 10 areextrudable thermoplastic polymers such as polyamides, nylons,polyesters, polyolefins or blends of polyolefins. For example,non-elastomeric, biodegradable polylactic acid can provide a sufficientrecovery percentage R₁ when stretched above its glass transitiontemperature of about 62° C.

[0015] The second component 12, like the first component 10, is amaterial that can be spun or otherwise formed into a continuous fiber.When the second component 12 is formed into a linear fiber, the linearfiber must be capable of being stretched and has a recovery percentageR₂, wherein R₁ is higher than R₂ The “recovery percentage R₂” is definedas the percent the component can recover after it has been stretched atleast 50% of its initial length and upon removal of the force applied tostretch it. When the first and second components, 10 and 12respectively, are formed into a linear fiber, the fiber must be capableof retracting or contracting from a stretched condition in order for thelinear fiber to be useful in an absorbent article. As referred toherein, the term “retracting” means the same thing as “contracting”.Desirably, the ratio of R₁/R₂ ranges from at least about 2 to about 100.Most desirably, the ratio of R₁/R₂ ranges from at least about 2 to about50. The reason for making R₁ greater than R₂ in a linear fiber is thatupon retraction or contraction of the first and second components, 10and 12 respectively, the 3-dimensional fiber will exhibit a verydesirable, predetermined structural configuration. This structuralconfiguration of the 3-dimensional fiber will display exceptionalelongation properties in at least one direction.

[0016] The linear fiber further obtains some of its unique propertieswhen the first component 10 makes up a volume percent of from about 30%to about 95% of the linear fiber and the second component 12 makes up avolume percent of from about 5% to about 70% of the linear fiber.Desirably, the first component 10 makes up a volume percent from about40% to about 80% of the linear fiber and the second component 12 makesup a volume percent of from about 20% to about 60% of the linear fiber.The volume of a solid linear fiber is calculated using the followingformula:

V=π(d ²/4)L ₁

[0017] where: V is the volume of the solid linear fiber;

[0018] π is a transcendental number, approximately 3.14159, representingthe ratio of the circumference to the diameter of a circle and appearingas a constant in a wide range of mathematical problems;

[0019] d is the diameter of the linear fiber; and

[0020] L₁ is the initial length of the linear fiber.

[0021] The above described ranges of volume percents for the firstcomponent 10 and for the second component 12 allow the linear fiber tobe stretched at least 50% to form a stretched linear fiber. The volumepercent of each of the first and second components, 10 and 12respectively, also plays a vital role in the retraction or contractionof the stretched fiber to a retracted length. By varying the volumepercent of each of the first and second components, 10 and 12respectively, one can manufacture a linear fiber that can be stretchedand then retracted to a predetermined configuration and with certaindesirable characteristics. At a later time, after such fibers are formedinto a disposable absorbent article, the contact with a body fluid willcause the absorbent article to swell which will allow the fibers toelongate in at least one direction before the fiber becomes linear. Asthe fibers elongate, they can extend and allow the absorbent structureto receive and store additional body fluids.

[0022] The first and second components, 10 and 12 respectively, arechemically, mechanically and/or physically adhered or joined to oneanother to prevent the fiber from splitting when the fiber is stretchedand then allowed to relax. The relaxed fiber will retract in length.Desirably, the first component 10 will be strongly adhered to the secondcomponent 12. In the core/sheath arrangement, the mechanical adhesionbetween the first and second components, 10 and 12 respectively, willcompliment any chemical and/or physical adhesion that is present and aidin preventing splitting or separation of the first component 10 from thesecond component 12. This splitting or separation occurs because onecomponent is capable of retracting to a greater extent than the othercomponent. If a strong mutual adhesion is not present, especially duringretraction, the two components can split apart and this is notdesirable. In a fiber formed of two components arranged in a side byside or wedge shape configuration, a strong chemical and/or physicaladhesion will prevent the first component 10 from splitting orseparating from the second component 12.

[0023] The second component 12 can be formed from polyolefins, such aspolyethylene or polypropylene, a polyester or a polyether. The secondcomponent 12 can also be a polyolefin resin, such as a fiber gradepolyethylene resin sold under the trade designation ASPUN® 6811A. ASPUN®is a registered trademark of Dow Chemical Company having an office inMidland, Mich. 48674. The second component 12 can also be a polyolefinresin, such as a homopolymer polypropylene such as Himont PF 304, and PF308, available from Basell North America, Inc. having an office at ThreeLittle Falls Centre, 2801 ° C. enterville Road, Wilmington, Del. 19808.Another example of a polyolefin resin from which the second component 12can be formed is polypropylene PP 3445 available from Exxon MobilCorporation having an office at 5959 Las Colinas Boulevard, Irving, Tex.75039-2298. Still other suitable polyolefinic materials that can be usedfor the second component 12 include random copolymers, such as a randomcopolymer containing propylene and ethylene. One such random copolymeris sold under the trade designation Exxon 9355, available from ExxonMobil Corporation having an office at 5959 Las Colinas Boulevard,Irving, Tex. 75039-2298.

[0024] The second component 12 can also be formed from a melt extrudablethermoplastic material that provides sufficient permanent deformationupon stretching. Such materials include, but are not limited to,aliphatic and aromatic polyesters, copolyesters, polyethers, polyolefinssuch as polypropylene or polyethylene, blends or copolymers thereof,polyamides and nylons. The second component 12 can further be formedfrom biodegradable resins, such as aliphatic polyesters. One suchaliphatic polyester is polylactic acid (PLA). Other biodegradable resinsinclude polycaprolactone, polybutylene succinate adipate andpolybutylene succinate. Polybutylene succinate adipate and polybutylenesuccinate resins are sold under the trade designation BIONOLLE® which isa registered trademark of Showa High Polymers having a sales office inNew York, N. Y. 1017. Additional biodegradable resins includecopolyester resin sold under the trade designation EASTAR BIO®. EASTARBIO® is a registered trademark of Eastman Chemical Company having anoffice in Kingsport, Tenn. 37662. Still other biodegradable resins thatcan be used for the second component 12 include polyhydroxyalkanoates(PHA) of varying composition and structure, and copolymers, blends andmixtures of the foregoing polymers. Specific examples of suitablebiodegradable polymer resins include BIONOLLE® 1003, 1020, 3020 and 3001resins commercially available from Itochu International. BIONOLLE® is aregistered trademark of Showa High Polymers having an office in NewYork, N. Y. 10017.

[0025] The second component 12 can also be formed from a water-solubleand swellable resin. Examples of such water-soluble and swellable resinsinclude polyethylene oxide (PEO) and polyvinyl alcohol (PVOH). Graftedpolyethylene oxide (gPEO) or chemically modified PEO can also be used.The water-soluble polymer can be blended with a biodegradable polymer toprovide for better processing, performance, and interactions withliquids.

[0026] It should be noted that the PEO resin can be chemically modifiedby reactive extrusion, grafting, block polymerization or branching toimprove its processability. The PEO resin can be modified by reactiveextrusion or grafting as described in U. S. Pat. No. 6,172,177 issued toWang et al. on Jan. 9, 2001.

[0027] Lastly, the second component 12 has a lower recovery percentageR₂ than the first component 10. The second component 12 can be formedfrom a material that exhibits a low elastic recovery. Materials fromwhich the second component 12 can be formed include, but are not limitedto polyolefin resins, polypropylene, polyethylene, polyethylene oxide(PEO), polyvinyl alcohol (PVOH), polyester and polyether. The secondcomponent 12 can be treated or modified with hydrophilic or hydrophobicsurfactants. Treatment of the second component 12 with a hydrophilicsurfactant will form a wettable surface for increasing interaction witha body fluid or liquid. For example, when the surface of the secondcomponent 12 is treated to be hydrophilic, it will become more wettablewhen contacted by a body fluid, especially urine. Treatment of thesecond component 12 with a hydrophobic surfactant will cause it to repela body fluid or liquid. Similar treatment of the first component 10 canalso be done to control its hydrophilic or hydrophobic characteristics.

[0028] Referring again to FIG. 1, the first and second components, 10and 12 respectively, are separately co-extruded in the two extruders 18and 24. The extruders 18 and 24 function in a manner well known to thoseskilled in the art. In short, the solid resin pellets or small particlesare heated up above their melting temperature and advanced along a pathby a rotating auger. The first component 10 is routed through a conduit26 while the second component 12 is simultaneously routed through aconduit 28 and both flow streams are directed into a spin pack 30. Amelt pump, not shown, can be positioned across one or both of theconduits 26 and 28 to regulate volumetric distribution, if needed. Thespin pack 30 is a device for making synthetic fibers. The spin pack 30includes a bottom plate having a plurality of holes or openings throughwhich the extruded material flows. The number of openings per squareinch in the spin pack 30 can range from about 5 to about 500 openingsper square inch. Desirably, the number of openings per square inch inthe spin pack 30 is from about 25 to about 250. More desirably, thenumber of openings per square inch in the spin pack 30 is from about 125to about 225. The size of each of the openings in the spin pack 30 canvary. A typical size opening can range from about 0.1 millimeter (mm) toabout 2.0 mm in diameter. Desirably, the size of each of the openings inthe spin pack 30 can range from about 0.3 mm to about 1.0 mm indiameter.

[0029] It should be noted that the openings in the spin pack 30 do nothave to be round or circular in cross-section but can have a bilobal,trilobal, square, triangular, rectangular, oval or any other geometricalcross-sectional configuration that is desired.

[0030] Referring to FIGS. 1 and 2, the first and second components, 10and 12 respectively, are directed into the spin pack 30 and are routedthrough the openings formed in the bottom plate in such a fashion thatthe first component 10 will form a core 32 while the second component 12will form a sheath 34 which surrounds the outside circumference of thecore 32. It should be noted that the first component 10 could form thesheath while the second component 12 could form the core, if desired.This core/sheath arrangement produces one configuration of a linear,bicomponent fiber 36. Bicomponent fibers having other cross-sectionalconfigurations can also be produced using the spin pack 30. For example,the bicomponent fiber can have a side by side configuration or acore/sheath design where the core is offset coaxially from the sheath.

[0031] One bicomponent fiber 36 will be formed for each opening formedin the plate within the spin pack 30. This enables a plurality ofcontinuous molten fibers 36, each having a predetermined diameter, tosimultaneously exit the spin pack 30 at a first speed. Each linear,bicomponent fiber 36 will be spaced apart and be separated from theadjacent fibers 36. The diameter of each bicomponent fiber 36 will bedictated by the size of the openings formed in the bottom plate of thespin pack 30. For example, as stated above, if the diameter of the holesor openings in the bottom plate range from about 0.1 mm to about 2.0 mm,then each of the molten fibers 36 can have a diameter which ranges fromabout 0.1 mm to about 2.0 mm. There is a tendency for the molten fibers36 to sometimes swell in cross-sectional area once they exit the openingformed in the plate but this expansion is relatively small.

[0032] The plurality of continuous molten fibers 36 are routed through aquench chamber 38 to form a plurality of cooled linear, bicomponentfibers 40. Desirably, the molten fibers 36 are directed downward fromthe spin pack 30 into the quench chamber 38. The reason for directingthe molten fibers 36 downward is that gravity can be used to assist inmoving the molten fibers 36. In addition, the vertical downward movementcan aid in keeping the fibers 36 separated from one another.

[0033] In the quench chamber 38, the continuous molten fibers 36 arecontacted by one or more streams of air. Normally, the temperature ofthe continuous molten fibers 36 exiting the spin pack 30 and enteringthe quench chamber 38 will be in the range of from about 150° C. toabout 250° C. The actual temperature of the molten fibers 36 will dependupon the material from which they are constructed, the meltingtemperature of such material, the amount of heat applied during theextrusion process, as well as other factors. Within the quench chamber38, the continuous molten fibers 36 are contacted and surrounded bylower temperature air. The temperature of the air can range from about0° C. to about 120° C. Desirably, the air is cooled or chilled so as toquickly cool the molten fibers 36. However, for certain materials usedto form the bicomponent fibers 36; it is advantageous to use ambient airor even heated air. However, for most elastomeric materials, the air iscooled or chilled to a temperature of from about 0° C. to about 400° C.More desirably, the air is cooled or chilled to a temperature of fromabout 15° C. to about 300° C. The lower temperature air can be directedtoward the molten fibers 36 at various angles but a horizontal ordownward angle seems to work best. The velocity of the incoming air canbe maintained or adjusted so as to efficiently cool the molten fibers36.

[0034] The cooled or chilled air will cause the continuous molten fibers36 to crystallize, assume a crystalline structure or phase separate andform a plurality of continuous cooled fibers 40. The cooled fibers 40are still linear in configuration at this time. Upon exiting the quenchchamber 38, the temperature of the cooled fibers 40 can range from about15° C. to about 100° C. Desirably, the temperature of the cooled fibers40 will range from about 20° C. to about 80° C. Most desirably, thetemperature of the cooled fibers 40 will range from about 25° C. toabout 60° C. The cooled fibers 40 will be at a temperature below themelting temperature of the first and second components, 10 and 12respectively, from which the fibers 40 were formed. The cooled fibers 40may have a soft plastic consistency at this stage.

[0035] The plurality of continuous cooled fibers 40 are then routed to adraw unit 42. The draw unit 42 can be vertically located below thequenching chamber 38 so as to take advantage of gravity. The draw unit42 can be a rotating roll around which all of the cooled fibers 40 arefunneled down into a rope or tow and are drawn by being wrapped at leastonce around the outer periphery of the rotating roll. The plurality ofcooled fibers 40 can be wrapped one or more times around the outerperiphery of the rotating roll. Desirably, the plurality of cooledfibers 40 can be wrapped 1½ times around the outer periphery of therotating roll wherein the fibers 40 accumulate into a rope or tow ofsolid fibers 44. Mechanical drawing involves subjecting the cooledfibers 40 to a mechanical force that will pull or draw the moltenmaterial exiting the spin pack 30.

[0036] The cooled fibers 40 are drawn down mainly from the molten stateand not from the cooled state. The downward force in the draw unit 42will cause the molten material to be lengthened and elongated into solidfibers 44. Lengthening of the molten material will usually shape,narrow, distort, or otherwise change the cross-sectional area of thesolid fibers 44. For example, if the molten material has a round orcircular cross-sectional area upon exiting the spin pack 30, the outsidediameter of the solid fibers 44 will be reduced. The amount that thediameter of the solid linear fibers 44 are reduced will depend uponseveral factors, including the amount the molten material is drawn, thedistance over which the fibers are drawn, the mechanical force used todraw the fibers, the spin line tension, etc. Desirably, the diameter ofthe solid linear fibers 44 will range from about 5 microns to about 10microns. More desirably, the diameter of the solid linear fibers 44 willl range from about 10 microns to about 50 microns. Most desirably, thediameter of the solid linear fibers 44 will range from about 10 micronsto about 30 microns.

[0037] The draw unit 42 will pull the cooled fibers 40 at a second speedthat is faster than the first speed displayed by the continuous moltenfibers 36 exiting the spin pack 30. This change in speed between thecontinuous molten fibers 36 and the continuous cooled fibers 40 enablesthe molten material to be lengthened and also to be reduced incross-sectional area. Upon exiting the draw unit 42, the cooled fibers40 will be solid fibers 44.

[0038] The plurality of solid fibers 44 exiting the draw unit 42 arethen routed in mass around a guide roll 45 to a spool 46. The advancingfibers 44 are circumferentially wound onto the periphery of the spool 46in the form of a rope. The spool 46 can be mounted in a support 48 andcan be made to rotate as the advancing fiber 44 is directed onto thespool 46. The spool 46 can be sized and shaped to accumulate apredetermined amount of solid fibers 44. The solid linear fibers 44 willl be accumulated on the spool 46 until the spool 46 is filled. At thistime the plurality of solid fibers 44 are cut or severed in mass by acutter 50. The advancing solid fibers 44 can then be directed ontoanother empty spool 46 that can be held in the support 48. The processof removing a filled spool 46 and replacing it with an empty spool 46,onto which the advancing fibers 44 can be accumulated, is well known tothose skilled in the art. This process can be automated so that theadvancing linear fibers 44 can be instantaneously and sequentiallydirected to the next available empty spool 46.

[0039] Each of the filled spools 46 can be stacked and stored for use ata later time at the same facility or they can be transported to anotherlocation. One feature of this invention is that the solid linear fibers44 do not have to be processed into crimped staple fibers nor formedinto a web in one continuous process. Instead, the method allows for aninterruption, such that the solid linear fibers 44 can be furtherprocessed at a later time and at a remote location, if desired.Alternatively, a continuous method could be employed wherein the spools46 would not need to be present.

[0040] Referring to FIG. 3, a schematic is depicted showing theunwinding of a plurality of linear fibers, stretching the fibers,cutting the fibers and then allowing the fibers to relax to form aplurality of 3-dimensional, staple fibers. The method allows for theplurality of linear fibers 44 that were circumferentially wound onto theouter periphery of the spool 46 to be unwound and directed to a heater52. The heater 52 is optional, but when present, will heat the pluralityof linear fibers 44 to an elevated temperature. The exact temperaturewill depend upon the composition of the first and second components, 10and 12 respectively, the diameter of the fibers 44, the amount thefibers 44 are to be stretched, the speed of the fibers 44, etc. It isalso possible at this time to apply a surface treatment to the pluralityof linear fibers 44, if desired. The application of a surface treatmenteither by spraying a chemical composition onto the fibers 44 or emersionof the fibers 44 in a liquid bath is well known to those skilled in theart. Various types of surface treatments can be applied to the fibers44.

[0041] The plurality of solid linear fibers 44 are then routed to astretching unit 54 where the plurality of linear fibers 44 is stretchedby at least about 50%. By “stretched” it is meant that the continuoussolid, linear fibers 44 are lengthened or elongated while in a solidstate. The stretching is caused by axial tension exerted on theplurality of linear fibers 44. As the linear fibers 44 are stretched,the cross-sectional area of the linear fibers 44 will l be reduced.Desirably, the amount of stretch imparted into the solid fibers 44 canrange from about 75% to about 1,000%. More desirably, the amount ofstretch imparted into the solid fibers, 44 can range from about 100% toabout 500%. Most desirably, amount of stretch imparted into the solidfibers 44 can range from about 150% to about 300%.

[0042] The stretching unit 54 is shown as including two pairs of spacedapart rolls. It should be noted that other forms of mechanicalstretching apparatus can be utilized. The first pair of rolls includes afirst roll 56 and a second roll 58. The first and second rolls, 56 and58 respectively, can be arranged in close contact with one another so asto form a nip 60 therebetween. The plurality of linear fibers 44,unwound from the spool 46, is routed around a portion of the peripheryof the first roll 56, through the nip 60 and around a portion of theperiphery of the second roll 58. The nip 60 can be adjusted such thatlittle or no pressure is exerted on the fibers 44. At least one of thefirst and second rolls, 56 and 58 respectively, is a driven roll whichis set to rotate at a first predetermined surface speed. This surfacespeed caused the plurality of linear fibers 44 to be advanced at thisspeed. The surface speed can vary depending upon one's uniquerequirements. However, a surface speed of between about 10 meters perminute (m/min) to about 1,000 m/min will be sufficient for mostapplications. Desirably, the surface speed will be equal to or less thanabout 500 m/min. A faster surface speed is usually more desirable than aslower surface speed in order to reduce the cost of manufacture.However, at very high speeds, the fibers can lose their stretchabilityand become brittle. This can cause the fibers to break before they reachthe desired percent of elongation.

[0043] Spaced downstream a desired distance from the first pair of rollsis the second pair of rolls. The second pair of rolls includes a firstroll 62 and a second roll 64. The first and second rolls, 62 and 64respectively, can be arranged in close contact with one another so as toform a nip 66 therebetween. The plurality of linear fibers 44 exitingthe first pair of rolls is routed around a portion of the periphery ofthe first roll 62, through the nip 66 and around a portion of theperiphery of the second roll 64. The nip 66 can be adjusted such thatlittle or no pressure is exerted on the fibers 44. At least one of thefirst and second rolls, 62 and 64 respectively, is a driven roll whichis set to rotate at a second predetermined surface speed. The secondpredetermined speed is faster than the first predetermined speed. Thisdifference in speed caused the plurality of fibers 44 to be stretchedlengthwise between the two pair of rolls to form a plurality ofstretched linear fibers 68.

[0044] It should be noted that multiple rolls or pairs of rolls thatrotate at different, and preferably increasing surface speeds, can alsobe utilized.

[0045] Optionally, positioned between the two pair of rolls, 56 and 58and 60 and 62 respectively, is a heater 70. The heater 70 is capable ofheating the plurality of linear fibers 44 to an elevated temperature.The exact temperature will depend upon the composition of the first andsecond components, 10 and 12 respectively, the diameter of the fibers44, the amount the fibers 44 are to be stretched, the speed of thefibers 44, etc.

[0046] The stretching of the plurality of fibers 44 within thestretching unit 54 will cause the cross-sectional area of each of thelinear fibers 44 to be reduced by about 5% to about 90% of thecross-sectional area of the linear fibers 44 unwound from the spool 46.Desirably, the cross-sectional area of each of the linear fibers 44 isreduced by about 10% to about 60% of the cross-sectional area of thelinear fibers 44 unwound from the spool 46. More desirably, thecross-sectional area of each of the linear fibers 44 is reduced by about20% to about 50% of the cross-sectional area of the linear fibers 44unwound from the spool 46.

[0047] The stretched, continuous linear fibers 68 will be relativelysmall in diameter or cross-sectional area. Desirably, the diameter ofthe stretched linear fibers 68 will range from about 5 microns to about50 microns. More desirably, the diameter of the stretched fibers 68 willrange from about 5 microns to about 30 microns. Most desirably, thediameter of the stretched linear fibers 68 will range from about 10microns to about 20 microns.

[0048] It should be noted that the stretched linear fibers 68 leavingthe second pair of rolls 62 and 64 can be heat set, if desired, beforebeing cut into staple fibers.

[0049] Still referring to FIG. 3, upon exiting the stretching unit 54,the plurality of stretched linear fibers 68 are cut or severed by arotary cutter 72 having at least one knife 74 secured thereto. Therotary cutter 72 cooperates with an anvil roll 76 and the cutter 72 andthe anvil roll 76 are arranged so that the stretched linear fiber 68passes therebetween. The rotary cutter 72 and the anvil roll 76 keep thestretched linear fiber 68 in tension until it has been cut by the knife74. It should be noted that other types of cutting mechanism can beutilized that are well known to those skilled in the cutting art. It isalso possible to position a cutter downstream of a pair of cooperatingrolls that maintain the stretched linear fiber 68 in tension. The rotarycutter 72 will cut the plurality of stretched fibers 68 into a pluralityof staple fibers 78, each having a predetermined length. The pluralityof stretched fibers 68 can be cut to a staple length of from about 5millimeters to about 500 millimeters. Desirably, the plurality ofstretched fibers 68 can be cut to a staple length of from about 10millimeters to about 50 millimeters. More desirably, the plurality ofstretched fibers 68 can be cut to a staple length of from about 12millimeters to about 25 millimeters. The plurality of cut staple fibers78 will instanteously start to relax. This relaxation allows the staplefibers 78 to retract or contract into a plurality of 3-dimensional,coiled fibers 80. The coiled fibers 80 have a shorter length than thecut stretched fiber 78. The coiled fibers 80 have a length ranging fromabout 3 millimeters (mm) to about 50 mm. Desirably, the coiled fibers 80have a length ranging from about 5 mm to about 25 mm. Most desirably,the coiled fibers 80 have a length ranging from about 5 mm to about 15mm. These coiled fibers 80 can be collected in a hopper or container 82.

[0050] Referring to FIG. 4, a portion of a 3-dimensional, staple fiber80 depicted in the shape of a helix or helical coil that has alongitudinal central axis x-x. By “3-dimensional fiber” is meant a fiberhaving an x, y and z component that is formed by virtue of coils and/orcurves regularly or irregularly spaced and whose extremities in the x, yand z planes form a locus of points which define a volume greater than alinear fiber. The 3-dimensional, coiled fibers 80 have a generallyhelical configuration. The helical configuration can extend along theentire length L of each of the 3-dimensional fibers 80 or it can occurover a portion of the length of the 3-dimensional fibers 80. Desirably,the coiled configuration extends over at least half of the length ofeach of the 3-dimensional fibers 80. More desirably, the coiledconfiguration extends from about 50% to about 90% of the length of eachof the 3-dimensional fibers 80. Most desirably, the coiled configurationextends from about 90% to about 100% of the length of each of the3-dimensional fibers 80. It should be noted that the coils can be formedin the clockwise or counterclockwise directions along at least a potionof the length of the 3-dimensional, staple fibers 80. It should also benoted that the configuration of each coil can vary along the length ofeach of the 3-dimensional, staple fibers 80.

[0051] Each of the 3-dimensional, staple fibers 80 have coils thatcircumscribes 360 degrees. The helical coils can be continuous ornon-continuous over either a portion of or over the entire length of the3-dimensional, staple fiber 80. Most desirably, the 3-dimensional,staple fibers 80 exhibit a continuous helical coil. The 3-dimensional,staple fiber 80 differs from a 2-dimensional fiber in that a2-dimensional fiber has only two components, for example, an “x” and a“y” component; an “x” and a “z” component, or a “y” and a “z” component.The 3-dimensional, staple fiber 80 has three components, an “x”component, a “y” component and a “z” component. Many crimp fibers are2-dimensional fibers that are flat and extend in only two directions. Acrimped fiber is typically a fiber that has been pressed or pinched intosmall, regular folds or ridges. A crimped fiber usually has a bend alongits length.

[0052] The 3-dimensional, staple fiber 80 has a non-linear configurationwhen it forms a helical coil. The 3-dimensional, staple fiber 80 alsohas an amplitude “A” that is measured perpendicular to a portion of itslength L The amplitude “A” of the 3-dimensional, staple fiber 80 canrange from about 10 microns to about 5,000 microns. Desirably, theamplitude “A” of the 3-dimensional, staple fiber 80 ranges from about 30microns to about 1,000 microns. Most desirably, the amplitude “A” of the3-dimensional, staple fiber 80 ranges from about 50 microns to about 500microns. The 3-dimensional, staple fiber 80 further has a frequency “F”measured at two locations separated by 360 degrees between adjacenthelical coils. The frequency “F” is used to denote the number of coilsor curls formed in each inch of the coiled fiber length. The frequency“F” can range from about 10 to about 1,000 coils per inch. Desirably,the frequency “F” can range from about 50 to about 500 coils per inch.It should be noted that the amplitude “A” and/or the frequency “F” canvary or remain constant along at least a portion of the length L, orover the entire length, of the 3-dimensional, staple fiber 80.Desirably, the amplitude “A” and the frequency “F” will remain constantover a majority of the length L. The amplitude “A” of the 3-dimensional,staple fiber 80 and the frequency “F” of the helical coils forming the3-dimensional, staple fiber 80 affect the overall reduction in thelength of the 3-dimensional, staple fiber 80 from it's stretchedcondition.

[0053] It should be noted that the deformation properties of the firstand second components, 10 and 12 respectively, will affect theconfiguration and size of the helical coils developed as the stretchedfibers 78 retracts into the 3-dimensional, coiled fibers 80.

[0054] The first and second components, 10 and 12 respectively, areadhered together in the spin pack 30 to form a plurality of continuousbicomponent fibers. The adhesion of the first component 10 to the secondcomponent 12 can be chemical, mechanical and/or physical. This abilityof the first and second components, 10 and 12 respectively, to adhere toone another will prevent splitting of the components 10 and 12 at alater time when one component retracts more than the other component.The first component 10 in the solid linear fiber 44 has an elongation ofat least about 50% deformation. The first component 10 is able torecover at least about 20% of the stretch deformation imparted thereto,based on its length after deformation. Desirably, the first component 10in the solid linear fiber 44 is able to recover at least about 50% ofits stretch deformation. If the first component 10 has an elongationbelow at least about 50%, the recovery or relaxation power may not besufficient to activate helical coiling of the 3-dimensional, staplefiber 80. Repetitive helical coils in the retracted 3-dimensional,staple fiber 80 are most desirable. A higher elongation than at leastabout 50% for the first component 10 is desirable. For example, anelongation of at least about 100% is good, an elongation exceeding 300%is better, and an elongation exceeding 400% is even better.

[0055] The second component 12 in the solid linear fiber 44 has a totaldeformation which includes a permanent unrecoverable deformation valueand a recoverable deformation value. The permanent unrecoverabledeformation value in a solid state, as a result of stretching, plasticyielding and/or drawing, is at least about 40%. The recoverabledeformation value is at least about 0.1%. A higher deformation than atleast about 50% for the second component 12 is desirable. A deformationof at least about 100% is good and a deformation exceeding about 300% iseven better. The plastic yielding and drawing results in thinning of thesecond component 12. Stretching in a solid state means that the secondcomponent 12 is stretched below its melting temperature. If the totaldeformation of the second component 12 is below at least about 50%, thesecond component 12 will fail and break during the stretching process.Also, at low deformation, the second component 12 does not provide asufficient level of permanent plastic yielding and thinning which isdesired for the formation of the repetitive helical coils in the3-dimensional, staple fibers 80. Stretching should not occur at very lowtemperatures because the fibers may be brittle and could break.Likewise, the fibers should not be stretched very quickly because thismight cause the fibers to break before reaching the desired percent ofelongation.

[0056] The percent elongation of the length of the 3-dimensional, coiledfiber 80 defined as the percent change in length by which the3-dimensional, coiled fiber 80 can be stretched before becoming straightor linear. The percent elongation can be expressed by the followingformula:

%E=100×(L ₁ −L)/L

[0057] where: % E is the percent elongation of the 3-dimensional, staplefiber 80;

[0058] L is the retracted length of the 3-dimensional, staple fiber 80;and

[0059] L₁ is the final length of the 3-dimensional, staple fiber 80 onceit is stretched into a straight or uncoiled configuration.

[0060] The retracted 3-dimensional, staple fiber 80 has the ability tobe subsequently elongated to at least 100% of its retracted length. Mostdesirably, the retracted 3-dimensional, staple fiber 80 can besubsequently elongated from about 150% to about 900% of its retractedlength. Even more desirably, the retracted 3-dimensional, staple fiber80 can be subsequently elongated from about 250% to about 500% of itsretracted length. Still more desirably, the retracted 3-dimensional,staple fiber 80 can be subsequently elongated from about 300% to about400% of its retracted length.

[0061] The 3-dimensional, staple fiber 80 exhibits exceptionalelongation properties in at least one direction before the fiber becomeslinear. Elongation is defined as the percent length by which the3-dimensional, staple fiber 80 can be stretched before it becomesstraight or linear. The direction of the elongation property of the3-dimensional, staple fiber 80 normally in the same direction as thelinear fiber 44 was stretched. In other words, the direction that theretracted 3-dimensional, staple fiber 80 able to subsequently elongatewill be opposite to the direction of its retraction. It is possible forthe retracted 3-dimensional, staple fiber 80 to have elongationproperties in two or more directions. For example, the retracted3-dimensional, staple fiber 80 can subsequently be elongated in both thex and y directions.

[0062] The 3-dimensional, staple fiber 80 obtained once the stretchedfiber 78 is allowed to relax or retract. The 3-dimensional, staple fiber80 able to acquire its helical profile by the difference in recoverypercentage R₁ of the first component 10 compared to the recoverypercentage R₂ of the second component 12. For example, since the firstcomponent 10 has a higher recovery percentage R₁ than the recoverypercentage R₂ of the second component 12, the first component 10 willwant to retract to a greater degree than the second component 12.However, both the first and second components, 10 and 12 respectively,will retract or contract the same amount since they are physically,chemically or mechanically adhered or joined to one another. Thecombination of the volume percent and the recovery percent of the firstand second components, 10 and 12 respectively, creates the unique3-dimensional configuration of the fiber 80. The retraction or recoveryof the first and second components, 10 and 12 respectively, establishesthe twist or coiling effect in the retracted 3-dimensional, staple fiber80. The amount of coiling obtained, as well as the shape and location ofthe coiling, can be controlled by the selection of materials that areused to construct the linear fiber 44. These three variables: the amountof coiling, the shape, and the location of the coiling, can also becontrolled by the volume of each component, as well as the amount thelinear fiber 44 is stretched. The time and temperature conditions underwhich the solid fibers 44 are stretched and allowed to retract can alsoaffect the finish profile of the retracted 3-dimensional, staple fiber80.

[0063] The first component 10 has a higher recovery percentage R₁ thanthe recovery percentage R₂ of the second component 12 and therefore thematerial from which the first component 10 is formed tends to be moretacky and elastic. For this reason, the material with the higherrecovery percentage R₁ is used to form the inner core while the materialhaving a lower recovery percentage R₂ tends to be used to form the outersheath. As the first and second components, 10 and 12 respectively, tryto retract from the stretched condition; the outer sheath will retractor contract less. This means that the first component 10 will not beable to retract fully to an amount that it could if it was by itself.This pent up force creates the twist or helical coil effect in theretracted 3-dimensional, staple fiber 80. By varying the materials usedto form the linear fiber 44 and by controlling the conditions to whichthe linear fiber 44 is stretched and then retracted, one can manufactureuniquely configured 3-dimensional, staple fibers 80 that willsubsequently elongate in a predetermined way. This characteristic hasbeen identified as being extremely useful in constructing disposableabsorbent articles. This characteristic may also exhibit beneficialfeatures in other articles as well.

[0064] The following Table 1 shows the recovery percent of individualmaterials that have been stretched to varying percentages. The materialforming each sample was cut out from a thin sheet of a particularthickness in the shape of a dogbone or dumbbell. The dogbone shapedsample had an initial length of 63 millimeters (mm) measured from afirst enlarged end to a second enlarged end. In between the twooppositely aligned, enlarged ends was a narrow section having a lengthof 18 mm and a width of 3 mm. The material was then placed in a tensiletester and stretched at a rate of 5 inches per minute, in the machinedirection of the material. This stretching caused the narrow section ofthe sample to elongate. The force used to stretch the sample was thenremoved and the sample was allowed to retract or recover. The retractedlength of the narrow section, known as the finished recovery length, wasmeasured and recorded as a percentage of the stretched length. One canextrapolate from this information that when such a material is combinedwith another material to form a linear fiber 44, those similar ranges ofrecovery or contraction can be experienced. TABLE 1 50% 100% 200% 700%Thickness Stretch stretched stretched stretched stretched Material inmils Temp. C.° & recovered & recovered & recovered & recoveredPolyurethane 5 25 24.5% 39.1% 54.4% — Polypropylene 3 25 5.4% 5.5% 5.1%— Polypropylene 3 75 — 8.7% 7.3% 6.4%

[0065] In Table 1, the dogbone shaped sample had a narrow section I₁located between its first and second enlarged ends. Each of the enlargedends of the dog bone sample was secured in a tensile tester and a forcewas applied causing the material to be stretched, in the machinedirection of the material, a predetermined amount at a specifictemperature. By stretching the sample, the narrow section is stretchedto a length I₂. The length I₂ is greater than the initial length I₁. Theforce exerted on the sample was then removed and the sample was allowedto retract such that the narrow section is shortened to a length I₃. Theretracted length I₃ is smaller than the stretched length I₂ but isgreater than the initial length I₁. The recovery percent (R %) of thedifferent materials that can be used in forming the fiber can becalculated using the following formula:

Recovery %=[(I ₂ −I ₃)/I ₂]×100

[0066] where: I₂ is the stretched length of the narrow section of thesample; and

[0067] I₃ is the retracted length of the narrow section of the sample.

[0068] It should be noted that the coiled fibers 80 can be mixed withother kinds of fibers, such as cellulose fibers, wood pulp fibers, othersynthetic fibers, etc. and/or a superabsorbent to form a web. The webcan be an airlaid web, an air formed web, a coform web, a wet laid wet,etc. The web can be used in various kinds of products. The web isespecially useful when used in a disposable absorbent article, such asan infant diaper, a training pant, an incontinent garment including apad, brief, pant and refastenable pant, a sanitary napkin or tampon, awet wipe product, etc. The method of admixing such fibers and/orsuperabsorbent particles is known to those skilled in the art. Thepercentage of each kind of fiber used to form the web can vary to meetone's particular needs. It should be noted that superabsorbent material,preferably in the form of particles, can be mixed with one or more kindsof fibers to form an absorbent web. The web can also be stabilizedand/or bonded using various methods known to those skilled in the art.

[0069] A recognized limitation of stabilized and bonded absorbent websis that the superabsorbent material present in the web is constrainedfrom swelling to its full capacity. The use of the 3-dimensional fibersof this invention will allow an absorbent web structure containingsuperabsorbent material to expand and accommodate the entire extent thesuperabsorbent material can swell.

[0070] It should also be noted that the coiled fibers 80 can belaminated to a stretchable material, an elastic film or elastic fibersto form a thin, absorbent or non-absorbent material. This laminatematerial can be used as the bodyside cover or facing layer on adisposable absorbent article such as a diaper, training pant,incontinence garment, sanitary napkin, etc. This laminate material canalso be used in health care products such as wound dressings, surgicalgowns, gloves, etc.

[0071] While the invention has been described in conjunction withseveral specific embodiments, it is to be understood that manyalternatives, modifications and variations will be apparent to thoseskilled in the art in light of the aforegoing description. Accordingly,this invention is intended to embrace all such alternatives,modifications and variations that fall within the spirit and scope ofthe appended claims.

We claim:
 1. A method of forming 3-dimensional fibers comprising thesteps of: a) co-extruding a first and a second component, said firstcomponent having a recovery percentage R₁ and said second componenthaving a recovery percentage R₂, wherein R₁ is higher than R₂; b)directing said first and second components through a spin pack to form aplurality of continuous molten fibers each having a predetermineddiameter; c) routing said plurality of molten fibers through a quenchchamber to form a plurality of cooled fibers; d) routing said pluralityof cooled fibers through a draw unit to form a plurality of solid fiberseach having a smaller diameter than said molten fibers; e) accumulatingsaid plurality of solid fibers and stretching said fibers by at leastabout 50 percent; f) cutting said stretched fibers into a plurality ofstaple fibers each having a predetermined length; and g) allowing saidstaple fibers to relax thereby forming coiled fibers, said firstcomponent of said coiled fibers having a strong mutual adhesion for saidsecond component of said coiled fiber to prevent splitting.
 2. Themethod of claim 1 wherein said coiled fibers are bicomponent fibers. 3.The method of claim 1 wherein each of said coiled fibers has acore/sheath cross-sectional configuration.
 4. The method of claim 1wherein said first and second components are mechanically adhered to oneanother.
 5. The method of claim 1 wherein said first and secondcomponents are chemically adhered to one another.
 6. The method of claim1 wherein said first and second components are physically adhered to oneanother.
 7. The method of claim 1 wherein said solid fibers are heatedprior to being stretched.
 8. The method of claim 1 wherein said solidfibers are heated while being stretched.
 9. The method of claim 1wherein said plurality of stretched fibers are cut by a rotary cutterinto predetermined lengths of from about 5 millimeters to about 500millimeters.
 10. A method of forming 3-dimensional, bicomponent fiberscomprising the steps of: a) co-extruding a first and a second component,said first component having a recovery percentage R₁ and said secondcomponent having a recovery percentage R₂, wherein R₁ is higher than R₂;b) directing said first and second components through a spin pack at afirst speed to form a plurality of continuous molten fibers each havinga predetermined diameter; c) routing said plurality of molten fibersthrough a quench chamber to form a plurality of cooled fibers; d)routing said plurality of cooled fibers through a draw unit at a secondspeed, said second speed being greater than said first speed, to form aplurality of solid fibers each having a smaller diameter than saidmolten fibers; e) accumulating said plurality of solid fibers andstretching said fibers by at least about 75 percent; f) cutting saidstretched fibers into a plurality of staple fibers each having apredetermined length; and g) allowing said staple fibers to relaxthereby forming coiled fibers, said first component of said coiledfibers having a strong mutual adhesion for said second component of saidcoiled fiber to prevent splitting.
 11. The method of claim 10 whereineach of said coiled fibers has a predetermined length of from about 5millimeters to about 50 millimeters.
 12. The method of claim 11 whereineach of said coiled fibers has a predetermined length of from about 5millimeters to about 25 millimeters.
 13. The method of claim 10 whereineach of said solid fibers are stretched from between about 50 percent toabout 1,000 percent.
 14. The method of claim 10 wherein each of saidcoiled fibers has a coil amplitude of from about 10 microns to about5,000 microns.
 15. The method of claim 10 wherein each of said coiledfibers has a frequency of coils ranging from about 10 to about 1,000coils per inch.
 16. The method of claim 10 wherein said second componentis polyolefin.
 17. A method of forming 3-dimensional, bicomponent fiberscomprising the steps of: a) co-extruding a first and a second component,said first component having a recovery percentage R₁ and said secondcomponent having a recovery percentage R₂, wherein R₁ is higher than R₂;b) directing said first and second components through a spin pack at afirst speed to form a plurality of continuous molten fibers each havinga predetermined diameter; c) routing said plurality of molten fibersthrough a quench chamber to form a plurality of cooled fibers; d)routing said plurality of cooled fibers through a draw unit at a secondspeed, said second speed being greater than said first speed, to form aplurality of solid fibers each having a smaller diameter than saidmolten fibers; e) accumulating said plurality of solid fibers on a spooland cutting said plurality of solid fibers when said spool is filled; f)unwinding said plurality of solid fibers from said spool and heatingsaid fibers to an elevated temperature; g) stretching said heated fibersby at least about 50 percent; h) cutting said stretched fibers into aplurality of staple fibers each having a predetermined length; and i)allowing said staple fibers to relax thereby forming coiled fibers, saidfirst component of said coiled fibers having a strong mutual adhesionfor said second component of said coiled fiber to prevent splitting. 18.The method of claim 17 wherein said coiled fibers have a helicalconfiguration.
 19. The method of claim 17 wherein each of said coiledfibers has a coil amplitude of from about 10 microns to about 5,000microns.
 20. The method of claim 17 wherein each of said solid fibersare stretched from between about 50 percent to about 1,000 percent. 21.The method of claim 17 wherein each of said coiled fibers has afrequency of coils ranging from about 10 to about 1,000 coils per inch.22. The method of claim 21 wherein each of said coiled fibers has afrequency of coils ranging from about 25 to about 250 coils per inch.23. A web formed from said 3-dimensional fibers of claim
 1. 24. The webof claim 23 wherein said web is an airlaid web.
 25. The web of claim 23wherein said web is an air formed web.
 26. The web of claim 23 whereinsaid web is a coform web.
 27. The web of claim 23 wherein said web is awet laid web.
 28. The web of claim 23 wherein superabsorbent material ispresent in said web.
 29. A web formed from said 3-dimensional fibers ofclaim
 17. 30. The web of claim 29 wherein superabsorbent material ispresent in said web.